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/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/*
Changes from V4.2.1
+ Introduced the configKERNEL_INTERRUPT_PRIORITY definition.
*/
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the PIC24 port.
*----------------------------------------------------------*/
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
/* Hardware specifics. */
#define portBIT_SET 1
#define portTIMER_PRESCALE 8
#define portINITIAL_SR 0
/* Defined for backward compatability with project created prior to
FreeRTOS.org V4.3.0. */
#ifndef configKERNEL_INTERRUPT_PRIORITY
#define configKERNEL_INTERRUPT_PRIORITY 1
#endif
/* Use _T1Interrupt as the interrupt handler name if the application writer has
not provided their own. */
#ifndef configTICK_INTERRUPT_HANDLER
#define configTICK_INTERRUPT_HANDLER _T1Interrupt
#endif /* configTICK_INTERRUPT_HANDLER */
/* The program counter is only 23 bits. */
#define portUNUSED_PR_BITS 0x7f
/* Records the nesting depth of calls to portENTER_CRITICAL(). */
UBaseType_t uxCriticalNesting = 0xef;
#if configKERNEL_INTERRUPT_PRIORITY != 1
#error If configKERNEL_INTERRUPT_PRIORITY is not 1 then the #32 in the following macros needs changing to equal the portINTERRUPT_BITS value, which is ( configKERNEL_INTERRUPT_PRIORITY << 5 )
#endif
#if defined( __PIC24E__ ) || defined ( __PIC24F__ ) || defined( __PIC24FK__ ) || defined( __PIC24H__ )
#ifdef __HAS_EDS__
#define portRESTORE_CONTEXT() \
asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \
"MOV [W0], W15 \n" \
"POP W0 \n" /* Restore the critical nesting counter for the task. */ \
"MOV W0, _uxCriticalNesting \n" \
"POP DSWPAG \n" \
"POP DSRPAG \n" \
"POP CORCON \n" \
"POP TBLPAG \n" \
"POP RCOUNT \n" /* Restore the registers from the stack. */ \
"POP W14 \n" \
"POP.D W12 \n" \
"POP.D W10 \n" \
"POP.D W8 \n" \
"POP.D W6 \n" \
"POP.D W4 \n" \
"POP.D W2 \n" \
"POP.D W0 \n" \
"POP SR " );
#else /* __HAS_EDS__ */
#define portRESTORE_CONTEXT() \
asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \
"MOV [W0], W15 \n" \
"POP W0 \n" /* Restore the critical nesting counter for the task. */ \
"MOV W0, _uxCriticalNesting \n" \
"POP PSVPAG \n" \
"POP CORCON \n" \
"POP TBLPAG \n" \
"POP RCOUNT \n" /* Restore the registers from the stack. */ \
"POP W14 \n" \
"POP.D W12 \n" \
"POP.D W10 \n" \
"POP.D W8 \n" \
"POP.D W6 \n" \
"POP.D W4 \n" \
"POP.D W2 \n" \
"POP.D W0 \n" \
"POP SR " );
#endif /* __HAS_EDS__ */
#endif /* MPLAB_PIC24_PORT */
#if defined( __dsPIC30F__ ) || defined( __dsPIC33F__ )
#define portRESTORE_CONTEXT() \
asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \
"MOV [W0], W15 \n" \
"POP W0 \n" /* Restore the critical nesting counter for the task. */ \
"MOV W0, _uxCriticalNesting \n" \
"POP PSVPAG \n" \
"POP CORCON \n" \
"POP DOENDH \n" \
"POP DOENDL \n" \
"POP DOSTARTH \n" \
"POP DOSTARTL \n" \
"POP DCOUNT \n" \
"POP ACCBU \n" \
"POP ACCBH \n" \
"POP ACCBL \n" \
"POP ACCAU \n" \
"POP ACCAH \n" \
"POP ACCAL \n" \
"POP TBLPAG \n" \
"POP RCOUNT \n" /* Restore the registers from the stack. */ \
"POP W14 \n" \
"POP.D W12 \n" \
"POP.D W10 \n" \
"POP.D W8 \n" \
"POP.D W6 \n" \
"POP.D W4 \n" \
"POP.D W2 \n" \
"POP.D W0 \n" \
"POP SR " );
#endif /* MPLAB_DSPIC_PORT */
#ifndef portRESTORE_CONTEXT
#error Unrecognised device selected
/* Note: dsPIC parts with EDS are not supported as there is no easy way to
recover the hardware stacked copies for DOCOUNT, DOHIGH, DOLOW. */
#endif
/*
* Setup the timer used to generate the tick interrupt.
*/
void vApplicationSetupTickTimerInterrupt( void );
/*
* See header file for description.
*/
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
{
uint16_t usCode;
UBaseType_t i;
const StackType_t xInitialStack[] =
{
0x1111, /* W1 */
0x2222, /* W2 */
0x3333, /* W3 */
0x4444, /* W4 */
0x5555, /* W5 */
0x6666, /* W6 */
0x7777, /* W7 */
0x8888, /* W8 */
0x9999, /* W9 */
0xaaaa, /* W10 */
0xbbbb, /* W11 */
0xcccc, /* W12 */
0xdddd, /* W13 */
0xeeee, /* W14 */
0xcdce, /* RCOUNT */
0xabac, /* TBLPAG */
/* dsPIC specific registers. */
#ifdef MPLAB_DSPIC_PORT
0x0202, /* ACCAL */
0x0303, /* ACCAH */
0x0404, /* ACCAU */
0x0505, /* ACCBL */
0x0606, /* ACCBH */
0x0707, /* ACCBU */
0x0808, /* DCOUNT */
0x090a, /* DOSTARTL */
0x1010, /* DOSTARTH */
0x1110, /* DOENDL */
0x1212, /* DOENDH */
#endif
};
/* Setup the stack as if a yield had occurred.
Save the low bytes of the program counter. */
usCode = ( uint16_t ) pxCode;
*pxTopOfStack = ( StackType_t ) usCode;
pxTopOfStack++;
/* Save the high byte of the program counter. This will always be zero
here as it is passed in a 16bit pointer. If the address is greater than
16 bits then the pointer will point to a jump table. */
*pxTopOfStack = ( StackType_t ) 0;
pxTopOfStack++;
/* Status register with interrupts enabled. */
*pxTopOfStack = portINITIAL_SR;
pxTopOfStack++;
/* Parameters are passed in W0. */
*pxTopOfStack = ( StackType_t ) pvParameters;
pxTopOfStack++;
for( i = 0; i < ( sizeof( xInitialStack ) / sizeof( StackType_t ) ); i++ )
{
*pxTopOfStack = xInitialStack[ i ];
pxTopOfStack++;
}
*pxTopOfStack = CORCON;
pxTopOfStack++;
#if defined(__HAS_EDS__)
*pxTopOfStack = DSRPAG;
pxTopOfStack++;
*pxTopOfStack = DSWPAG;
pxTopOfStack++;
#else /* __HAS_EDS__ */
*pxTopOfStack = PSVPAG;
pxTopOfStack++;
#endif /* __HAS_EDS__ */
/* Finally the critical nesting depth. */
*pxTopOfStack = 0x00;
pxTopOfStack++;
return pxTopOfStack;
}
/*-----------------------------------------------------------*/
BaseType_t xPortStartScheduler( void )
{
/* Setup a timer for the tick ISR. */
vApplicationSetupTickTimerInterrupt();
/* Restore the context of the first task to run. */
portRESTORE_CONTEXT();
/* Simulate the end of the yield function. */
asm volatile ( "return" );
/* Should not reach here. */
return pdTRUE;
}
/*-----------------------------------------------------------*/
void vPortEndScheduler( void )
{
/* Not implemented in ports where there is nothing to return to.
Artificially force an assert. */
configASSERT( uxCriticalNesting == 1000UL );
}
/*-----------------------------------------------------------*/
/*
* Setup a timer for a regular tick.
*/
__attribute__(( weak )) void vApplicationSetupTickTimerInterrupt( void )
{
const uint32_t ulCompareMatch = ( ( configCPU_CLOCK_HZ / portTIMER_PRESCALE ) / configTICK_RATE_HZ ) - 1;
/* Prescale of 8. */
T1CON = 0;
TMR1 = 0;
PR1 = ( uint16_t ) ulCompareMatch;
/* Setup timer 1 interrupt priority. */
IPC0bits.T1IP = configKERNEL_INTERRUPT_PRIORITY;
/* Clear the interrupt as a starting condition. */
IFS0bits.T1IF = 0;
/* Enable the interrupt. */
IEC0bits.T1IE = 1;
/* Setup the prescale value. */
T1CONbits.TCKPS0 = 1;
T1CONbits.TCKPS1 = 0;
/* Start the timer. */
T1CONbits.TON = 1;
}
/*-----------------------------------------------------------*/
void vPortEnterCritical( void )
{
portDISABLE_INTERRUPTS();
uxCriticalNesting++;
}
/*-----------------------------------------------------------*/
void vPortExitCritical( void )
{
configASSERT( uxCriticalNesting );
uxCriticalNesting--;
if( uxCriticalNesting == 0 )
{
portENABLE_INTERRUPTS();
}
}
/*-----------------------------------------------------------*/
void __attribute__((__interrupt__, auto_psv)) configTICK_INTERRUPT_HANDLER( void )
{
/* Clear the timer interrupt. */
IFS0bits.T1IF = 0;
if( xTaskIncrementTick() != pdFALSE )
{
portYIELD();
}
}